Maleness in Allomyces arbuscula

SUMMARY: Coloured gametangia in the male and female hybrid Allomyces arbuscula × A. macrogynus and in various mutants of A. arbuscula were essentially of two sizes, large and small, measuring approximately 1847 ± 347 μm2and 1032 ± 179 μm2respectively. The large coloured gametangia were the same size as those of the female wild-type. The carotene content of the culture increased with masculinization and with increases in the proportion of large coloured gametangia. Relative gametangial size alone is not a reliable phenotypic marker of sexuality in Allomyces.